/*
 * Copyright (c) JForum Team
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, 
 * with or without modification, are permitted provided 
 * that the following conditions are met:
 * 
 * 1) Redistributions of source code must retain the above 
 * copyright notice, this list of conditions and the 
 * following  disclaimer.
 * 2)  Redistributions in binary form must reproduce the 
 * above copyright notice, this list of conditions and 
 * the following disclaimer in the documentation and/or 
 * other materials provided with the distribution.
 * 3) Neither the name of "Rafael Steil" nor 
 * the names of its contributors may be used to endorse 
 * or promote products derived from this software without 
 * specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT 
 * HOLDERS AND CONTRIBUTORS "AS IS" AND ANY 
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, 
 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR 
 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL 
 * THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE 
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES 
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, 
 * OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER 
 * IN CONTRACT, STRICT LIABILITY, OR TORT 
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN 
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE
 * 
 * Created on Jan 26, 2005 4:42:44 PM
 * The JForum Project
 * http://www.jforum.net
 */
package net.jforum.dao.oracle;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.sql.Blob;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

import net.jforum.JForumExecutionContext;
import net.jforum.exceptions.DatabaseException;
import net.jforum.util.DbUtils;
import oracle.sql.BLOB;

/**
 * @author Dmitriy Kiriy
 * @version $Id: OracleUtils.java,v 1.14 2007/08/31 22:56:40 rafaelsteil Exp $
 */
public class OracleUtils {
    public static String readBlobUTF16BinaryStream(ResultSet rs,
	    String fieldName) throws SQLException {
	try {
	    Blob clob = rs.getBlob(fieldName);

	    InputStream is = clob.getBinaryStream();
	    StringBuffer sb = new StringBuffer();

	    int readedBytes;
	    int bufferSize = 4096;

	    do {
		byte[] bytes = new byte[bufferSize];

		readedBytes = is.read(bytes);

		if (readedBytes > 0) {
		    String readed = new String(bytes, 0, readedBytes, "UTF-16");
		    sb.append(readed);
		}
	    } while (readedBytes == bufferSize);

	    is.close();
	    return sb.toString();
	} catch (IOException e) {
	    throw new DatabaseException(e);
	}
    }

    /**
     * The query should look like:
     * 
     * SELECT blob_field from any_table WHERE id = ? FOR UPDATE
     * 
     * BUT KEEP IN MIND:
     * 
     * When you insert record in previous step, it should go with empty_blob()
     * like:
     * 
     * INSERT INTO jforum_posts_text ( post_text ) VALUES (EMPTY_BLOB())
     * 
     * @param query
     *            String
     * @param idForQuery
     *            int
     * @param value
     *            String
     * @throws SQLException
     */
    public static void writeBlobUTF16BinaryStream(String query, int idForQuery,
	    String value) throws Exception {
	PreparedStatement p = null;
	ResultSet rs = null;
	OutputStream blobWriter = null;

	try {
	    p = JForumExecutionContext.getConnection().prepareStatement(query);
	    p.setInt(1, idForQuery);

	    rs = p.executeQuery();
	    rs.next();
	    Blob text = rs.getBlob(1);

	    if (text instanceof BLOB) {
		blobWriter = ((BLOB) text).getBinaryOutputStream();
	    } else {
		blobWriter = text.setBinaryStream(0);
	    }

	    blobWriter.write(value.getBytes("UTF-16"));

	    blobWriter.close();
	} catch (IOException e) {
	    throw new DatabaseException(e);
	} finally {
	    if (blobWriter != null) {
		blobWriter.close();
	    }

	    DbUtils.close(rs, p);
	}
    }
}
